DIFFERENTIATING PHYSICAL RANDOM ACCESS CHANNEL REPETITION NUMBERS

Description

BACKGROUND

Field of the Disclosure

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for differentiating physical random access channel (PRACH) repetition numbers.

Description of Related Art

Wireless communications systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, or other similar types of services. These wireless communications systems may employ multiple-access technologies capable of supporting communications with multiple users by sharing available wireless communications system resources with those users.

Although wireless communications systems have made great technological advancements over many years, challenges still exist. For example, complex and dynamic environments can still attenuate or block signals between wireless transmitters and wireless receivers. Accordingly, there is a continuous desire to improve the technical performance of wireless communications systems, including, for example: improving speed and data carrying capacity of communications, improving efficiency of the use of shared communications mediums, reducing power used by transmitters and receivers while performing communications, improving reliability of wireless communications, avoiding redundant transmissions and/or receptions and related processing, improving the coverage area of wireless communications, increasing the number and types of devices that can access wireless communications systems, increasing the ability for different types of devices to intercommunicate, increasing the number and type of wireless communications mediums available for use, and the like. Consequently, there exists a need for further improvements in wireless communications systems to overcome the aforementioned technical challenges and others.

SUMMARY

One aspect provides a method for wireless communications by a network entity. The method includes receiving at least one physical random access channel (PRACH) repetition, of a group of PRACH repetitions; determining a number of PRACH repetitions in the group, based on at least one resource associated with the at least one PRACH repetition; and processing the group of PRACH repetitions, in accordance with the determination.

Another aspect provides a method for wireless communications by a user equipment (UE). The method includes selecting at least one resource for at least one PRACH repetition of a group of PRACH repetitions, wherein the selection is based on a number of PRACH repetitions in the group; and transmitting the PRACH repetitions, in accordance with the selection.

Other aspects provide: an apparatus operable, configured, or otherwise adapted to perform any one or more of the aforementioned methods and/or those described elsewhere herein; a non-transitory, computer-readable media comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to perform the aforementioned methods as well as those described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising code for performing the aforementioned methods as well as those described elsewhere herein; and/or an apparatus comprising means for performing the aforementioned methods as well as those described elsewhere herein. By way of example, an apparatus may comprise a processing system, a device with a processing system, or processing systems cooperating over one or more networks.

The following description and the appended figures set forth certain features for purposes of illustration.

BRIEF DESCRIPTION OF DRAWINGS

The appended figures depict certain features of the various aspects described herein and are not to be considered limiting of the scope of this disclosure.

FIG. 1 depicts an example wireless communications network.

FIG. 2 depicts an example disaggregated base station architecture.

FIG. 3 depicts aspects of an example base station and an example user equipment.

FIGS. 4A, 4B, 4C, and 4D depict various example aspects of data structures for a wireless communications network.

FIG. 5 depicts a call flow diagram illustrating an example four-step random access channel (RACH) procedure, in accordance with certain aspects of the present disclosure.

FIG. 6 depicts an example association of SSBs to RACH occasions (ROs).

FIG. 7 depicts an example call flow diagram, in accordance with certain aspects of the present disclosure.

FIG. 8 depicts an example of differentiating PRACH repetition numbers based on frequency, in accordance with certain aspects of the present disclosure.

FIG. 9 depicts an example of differentiating PRACH repetition numbers based on time domain locations of ROs, in accordance with certain aspects of the present disclosure.

FIG. 10 depicts a method for wireless communications.

FIG. 11 depicts a method for wireless communications.

FIG. 12 depicts aspects of an example communications device.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatuses, methods, processing systems, and computer-readable mediums for differentiating physical random access channel (PRACH) repetition numbers.

A Physical Random Access Channel (PRACH) generally refers to a channel used by user equipment (UE) to initiate communication with a base station (e.g., a gNB) in a cellular network. For example, as part of a random access (RA) channel procedure, the UE may send a preamble on the PRACH, after detecting a synchronization signal block (SSB) transmitted by the gNB. After successfully decoding a PRACH preamble, the gNB may respond with a Random Access Response (RAR) containing a Temporary Cell Identifier (TCI) and a timing advance (TA) value. The UE uses the TCI and TA to synchronize with the gNB and to access the network.

In some cases, to increase the chance of successful decoding, a PRACH may be sent with repetition. The use of repetition may enhance coverage, for example, allowing a base station to perform combining of signals received over multiple random access channel (RACH) occasions (ROs). A higher number of repetitions can increase the chance of successful communication, but it also increases the UE's power consumption and delay. PRACH repetitions may be transmitted in random access channel (RACH) occasions (ROs).

In PRACH, an RO generally refers to a specific time and frequency resource that maps to an SSB. The UE transmits a preamble sequence, from a set of preamble sequences, to initiate a Random Access (RA) procedure. The gNB uses the timing and frequency information associated with the RO to detect and decode the preamble and responds with the RAR. A number of ROs used for PRACH repetitions may be configured to balance a trade-off between the probability of successful RA, network overhead, and UE power consumption.

The number of PRACH repetitions may determine a size of a window, referred to as an RAR window, in which the UE monitors for an RAR after PRACH transmission. Unfortunately, in certain cases, the UE and network may not be aligned regarding the number of PRACH repetitions, which may result in ambiguity. For example, if a UE has the flexibility to select the number of PRACH repetitions (e.g., based on channel conditions and/or location), the network entity may not know how many PRACH repetitions will be sent. As a result, the UE and gNB may not be in agreement regarding the RAR window. Further, not knowing the number of PRACH repetitions may impact gNB performance. For example, the gNB may not take advantage of potential decoding gain by combining PRACH transmissions and/or the gNB may waste resources attempting blind decoding (for PRACH repetitions not sent).

Aspects of the present disclosure provide techniques for differentiating PRACH repetition numbers, which may help resolve the ambiguity at the UE and gNB. For example, a number of PRACH repetitions in a group may be determined based on at least one resource associated with at least one PRACH repetition of the group of PRACH repetitions.

Utilization of the techniques disclosed herein may, thus, allow a network entity to determine a number of PRACH repetitions, which may help optimize network performance. For example, knowing the number of PRACH repetitions used by the UE may increase the likelihood of successful RACH procedures, allowing a UE to establish a connection sooner.

Introduction to Wireless Communications Networks

The techniques and methods described herein may be used for various wireless communications networks. While aspects may be described herein using terminology commonly associated with 3G, 4G, and/or 5G wireless technologies, aspects of the present disclosure may likewise be applicable to other communications systems and standards not explicitly mentioned herein.

FIG. 1 depicts an example of a wireless communications network 100, in which aspects described herein may be implemented.

Generally, wireless communications network 100 includes various network entities (alternatively, network elements or network nodes). A network entity is generally a communications device and/or a communications function performed by a communications device (e.g., a user equipment (UE), a base station (BS), a component of a BS, a server, etc.). For example, various functions of a network as well as various devices associated with and interacting with a network may be considered network entities. Further, wireless communications network 100 includes terrestrial aspects, such as ground-based network entities (e.g., BSs 102), and non-terrestrial aspects, such as satellite 140 and aircraft 145, which may include network entities on-board (e.g., one or more BSs) capable of communicating with other network elements (e.g., terrestrial BSs) and user equipments.

In the depicted example, wireless communications network 100 includes BSs 102, UEs 104, and one or more core networks, such as an Evolved Packet Core (EPC) 160 and 5G Core (5GC) network 190, which interoperate to provide communications services over various communications links, including wired and wireless links.

FIG. 1 depicts various example UEs 104, which may more generally include: a cellular phone, smart phone, session initiation protocol (SIP) phone, laptop, personal digital assistant (PDA), satellite radio, global positioning system, multimedia device, video device, digital audio player, camera, game console, tablet, smart device, wearable device, vehicle, electric meter, gas pump, large or small kitchen appliance, healthcare device, implant, sensor/actuator, display, internet of things (IoT) devices, always on (AON) devices, edge processing devices, or other similar devices. UEs 104 may also be referred to more generally as a mobile device, a wireless device, a wireless communications device, a station, a mobile station, a subscriber station, a mobile subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a remote device, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, and others.

BSs 102 wirelessly communicate with (e.g., transmit signals to or receive signals from) UEs 104 via communications links 120. The communications links 120 between BSs 102 and UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a BS 102 and/or downlink (DL) (also referred to as forward link) transmissions from a BS 102 to a UE 104. The communications links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity in various aspects.

BSs 102 may generally include: a NodeB, enhanced NodeB (eNB), next generation enhanced NodeB (ng-eNB), next generation NodeB (gNB or gNodeB), access point, base transceiver station, radio base station, radio transceiver, transceiver function, transmission reception point, and/or others. Each of BSs 102 may provide communications coverage for a respective geographic coverage area 110, which may sometimes be referred to as a cell, and which may overlap in some cases (e.g., small cell 102′ may have a coverage area 110′ that overlaps the coverage area 110 of a macro cell). A BS may, for example, provide communications coverage for a macro cell (covering relatively large geographic area), a pico cell (covering relatively smaller geographic area, such as a sports stadium), a femto cell (relatively smaller geographic area (e.g., a home)), and/or other types of cells.

While BSs 102 are depicted in various aspects as unitary communications devices, BSs 102 may be implemented in various configurations. For example, one or more components of a base station may be disaggregated, including a central unit (CU), one or more distributed units (DUs), one or more radio units (RUS), a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC), or a Non-Real Time (Non-RT) RIC, to name a few examples. In another example, various aspects of a base station may be virtualized. More generally, a base station (e.g., BS 102) may include components that are located at a single physical location or components located at various physical locations. In examples in which a base station includes components that are located at various physical locations, the various components may each perform functions such that, collectively, the various components achieve functionality that is similar to a base station that is located at a single physical location. In some aspects, a base station including components that are located at various physical locations may be referred to as a disaggregated radio access network architecture, such as an Open RAN (O-RAN) or Virtualized RAN (VRAN) architecture. FIG. 2 depicts and describes an example disaggregated base station architecture.

Different BSs 102 within wireless communications network 100 may also be configured to support different radio access technologies, such as 3G, 4G, and/or 5G. For example, BSs 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC 160 through first backhaul links 132 (e.g., an S1 interface). BSs 102 configured for 5G (e.g., 5G NR or Next Generation RAN (NG-RAN)) may interface with 5GC 190 through second backhaul links 184. BSs 102 may communicate directly or indirectly (e.g., through the EPC 160 or 5GC 190) with each other over third backhaul links 134 (e.g., X2 interface), which may be wired or wireless.

Wireless communications network 100 may subdivide the electromagnetic spectrum into various classes, bands, channels, or other features. In some aspects, the subdivision is provided based on wavelength and frequency, where frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, or a subband. For example, 3GPP currently defines Frequency Range 1 (FR1) as including 410 MHz-7125 MHz, which is often referred to (interchangeably) as “Sub-6 GHz”. Similarly, 3GPP currently defines Frequency Range 2 (FR2) as including 24,250 MHz-52,600 MHZ, which is sometimes referred to (interchangeably) as a “millimeter wave” (“mmW” or “mmWave”). A base station configured to communicate using mmWave/near mmWave radio frequency bands (e.g., a mmWave base station such as BS 180) may utilize beamforming (e.g., 182) with a UE (e.g., 104) to improve path loss and range.

The communications links 120 between BSs 102 and, for example, UEs 104, may be through one or more carriers, which may have different bandwidths (e.g., 5, 10, 15, 20, 100, 400, and/or other MHz), and which may be aggregated in various aspects. Carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL).

Communications using higher frequency bands may have higher path loss and a shorter range compared to lower frequency communications. Accordingly, certain base stations (e.g., 180 in FIG. 1) may utilize beamforming 182 with a UE 104 to improve path loss and range. For example, BS 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming. In some cases, BS 180 may transmit a beamformed signal to UE 104 in one or more transmit directions 182′. UE 104 may receive the beamformed signal from the BS 180 in one or more receive directions 182″. UE 104 may also transmit a beamformed signal to the BS 180 in one or more transmit directions 182″. BS 180 may also receive the beamformed signal from UE 104 in one or more receive directions 182′. BS 180 and UE 104 may then perform beam training to determine the best receive and transmit directions for each of BS 180 and UE 104. Notably, the transmit and receive directions for BS 180 may or may not be the same. Similarly, the transmit and receive directions for UE 104 may or may not be the same.

Wireless communications network 100 further includes a Wi-Fi AP 150 in communication with Wi-Fi stations (STAs) 152 via communications links 154 in, for example, a 2.4 GHz and/or 5 GHz unlicensed frequency spectrum.

Certain UEs 104 may communicate with each other using device-to-device (D2D) communications link 158. D2D communications link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), and/or a physical sidelink feedback channel (PSFCH).

EPC 160 may include various functional components, including: a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and/or a Packet Data Network (PDN) Gateway 172, such as in the depicted example. MME 162 may be in communication with a Home Subscriber Server (HSS) 174. MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, MME 162 provides bearer and connection management.

Generally, user Internet protocol (IP) packets are transferred through Serving Gateway 166, which itself is connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation as well as other functions. PDN Gateway 172 and the BM-SC 170 are connected to IP Services 176, which may include, for example, the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switched (PS) streaming service, and/or other IP services.

BM-SC 170 may provide functions for MBMS user service provisioning and delivery. BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and/or may be used to schedule MBMS transmissions. MBMS Gateway 168 may be used to distribute MBMS traffic to the BSs 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and/or may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

5GC 190 may include various functional components, including: an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. AMF 192 may be in communication with Unified Data Management (UDM) 196.

AMF 192 is a control node that processes signaling between UEs 104 and 5GC 190. AMF 192 provides, for example, quality of service (QOS) flow and session management.

Internet protocol (IP) packets are transferred through UPF 195, which is connected to the IP Services 197, and which provides UE IP address allocation as well as other functions for 5GC 190. IP Services 197 may include, for example, the Internet, an intranet, an IMS, a PS streaming service, and/or other IP services.

In various aspects, a network entity or network node can be implemented as an aggregated base station, as a disaggregated base station, a component of a base station, an integrated access and backhaul (IAB) node, a relay node, a sidelink node, to name a few examples.

FIG. 2 depicts an example disaggregated base station 200 architecture. The disaggregated base station 200 architecture may include one or more central units (CUs) 210 that can communicate directly with a core network 220 via a backhaul link, or indirectly with the core network 220 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a Non-Real Time (Non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) Framework 205, or both). A CU 210 may communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an F1 interface. The DUs 230 may communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RUs 240 may communicate with respective UEs 104 via one or more radio frequency (RF) access links. In some implementations, the UE 104 may be simultaneously served by multiple RUs 240.

Each of the units, e.g., the CUS 210, the DUs 230, the RUs 240, as well as the Near-RT RICs 225, the Non-RT RICs 215 and the SMO Framework 205, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communications interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally or alternatively, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a radio frequency (RF) transceiver), configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

In some aspects, the CU 210 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 210. The CU 210 may be configured to handle user plane functionality (e.g., Central Unit-User Plane (CU-UP)), control plane functionality (e.g., Central Unit-Control Plane (CU-CP)), or a combination thereof. In some implementations, the CU 210 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the E1 interface when implemented in an O-RAN configuration. The CU 210 can be implemented to communicate with the DU 230, as necessary, for network control and signaling.

The DU 230 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 240. In some aspects, the DU 230 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3^rd Generation Partnership Project (3GPP). In some aspects, the DU 230 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 230, or with the control functions hosted by the CU 210.

Lower-layer functionality can be implemented by one or more RUs 240. In some deployments, an RU 240, controlled by a DU 230, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like), or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU(s) 240 can be implemented to handle over the air (OTA) communications with one or more UEs 104. In some implementations, real-time and non-real-time aspects of control and user plane communications with the RU(s) 240 can be controlled by the corresponding DU 230. In some scenarios, this configuration can enable the DU(s) 230 and the CU 210 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

The SMO Framework 205 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 205 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO Framework 205 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 290) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface). Such virtualized network elements can include, but are not limited to, CUs 210, DUs 230, RUs 240 and Near-RT RICs 225. In some implementations, the SMO Framework 205 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 211, via an O1 interface. Additionally, in some implementations, the SMO Framework 205 can communicate directly with one or more RUs 240 via an O1 interface. The SMO Framework 205 also may include a Non-RT RIC 215 configured to support functionality of the SMO Framework 205.

The Non-RT RIC 215 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, Artificial Intelligence/Machine Learning (AI/ML) workflows including model training and updates, or policy-based guidance of applications/features in the Near-RT RIC 225. The Non-RT RIC 215 may be coupled to or communicate with (such as via an A1 interface) the Near-RT RIC 225. The Near-RT RIC 225 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 210, one or more DUs 230, or both, as well as an O-eNB, with the Near-RT RIC 225.

In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC 225, the Non-RT RIC 215 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 225 and may be received at the SMO Framework 205 or the Non-RT RIC 215 from non-network data sources or from network functions. In some examples, the Non-RT RIC 215 or the Near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 215 may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework 205 (such as reconfiguration via 01) or via creation of RAN management policies (such as A1 policies).

FIG. 3 depicts aspects of an example BS 102 and a UE 104.

Generally, BS 102 includes various processors (e.g., 320, 330, 338, and 340), antennas 334a-t (collectively 334), transceivers 332a-t (collectively 332), which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., data source 312) and wireless reception of data (e.g., data sink 339). For example, BS 102 may send and receive data between BS 102 and UE 104. BS 102 includes controller/processor 340, which may be configured to implement various functions described herein related to wireless communications.

Generally, UE 104 includes various processors (e.g., 358, 364, 366, and 380), antennas 352a-r (collectively 352), transceivers 354a-r (collectively 354), which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., retrieved from data source 362) and wireless reception of data (e.g., provided to data sink 360). UE 104 includes controller/processor 380, which may be configured to implement various functions described herein related to wireless communications.

In regards to an example downlink transmission, BS 102 includes a transmit processor 320 that may receive data from a data source 312 and control information from a controller/processor 340. The control information may be for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical HARQ indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), and/or others. The data may be for the physical downlink shared channel (PDSCH), in some examples.

Transmit processor 320 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Transmit processor 320 may also generate reference symbols, such as for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS).

Transmit (TX) multiple-input multiple-output (MIMO) processor 330 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) in transceivers 332a-332t. Each modulator in transceivers 332a-332t may process a respective output symbol stream to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from the modulators in transceivers 332a-332t may be transmitted via the antennas 334a-334t, respectively.

In order to receive the downlink transmission, UE 104 includes antennas 352a-352r that may receive the downlink signals from the BS 102 and may provide received signals to the demodulators (DEMODs) in transceivers 354a-354r, respectively. Each demodulator in transceivers 354a-354r may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples to obtain received symbols.

MIMO detector 356 may obtain received symbols from all the demodulators in transceivers 354a-354r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor 358 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 104 to a data sink 360, and provide decoded control information to a controller/processor 380.

In regards to an example uplink transmission, UE 104 further includes a transmit processor 364 that may receive and process data (e.g., for the PUSCH) from a data source 362 and control information (e.g., for the physical uplink control channel (PUCCH)) from the controller/processor 380. Transmit processor 364 may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS)). The symbols from the transmit processor 364 may be precoded by a TX MIMO processor 366 if applicable, further processed by the modulators in transceivers 354a-354r (e.g., for SC-FDM), and transmitted to BS 102.

At BS 102, the uplink signals from UE 104 may be received by antennas 334a-t, processed by the demodulators in transceivers 332a-332t, detected by a MIMO detector 336 if applicable, and further processed by a receive processor 338 to obtain decoded data and control information sent by UE 104. Receive processor 338 may provide the decoded data to a data sink 339 and the decoded control information to the controller/processor 340.

Memories 342 and 382 may store data and program codes for BS 102 and UE 104, respectively.

Scheduler 344 may schedule UEs for data transmission on the downlink and/or uplink.

In various aspects, BS 102 may be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” may refer to various mechanisms of outputting data, such as outputting data from data source 312, scheduler 344, memory 342, transmit processor 320, controller/processor 340, TX MIMO processor 330, transceivers 332a-t, antenna 334a-t, and/or other aspects described herein. Similarly, “receiving” may refer to various mechanisms of obtaining data, such as obtaining data from antennas 334a-t, transceivers 332a-t, RX MIMO detector 336, controller/processor 340, receive processor 338, scheduler 344, memory 342, and/or other aspects described herein.

In various aspects, UE 104 may likewise be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” may refer to various mechanisms of outputting data, such as outputting data from data source 362, memory 382, transmit processor 364, controller/processor 380, TX MIMO processor 366, transceivers 354a-t, antenna 352a-t, and/or other aspects described herein. Similarly, “receiving” may refer to various mechanisms of obtaining data, such as obtaining data from antennas 352a-t, transceivers 354a-t, RX MIMO detector 356, controller/processor 380, receive processor 358, memory 382, and/or other aspects described herein.

In some aspects, a processor may be configured to perform various operations, such as those associated with the methods described herein, and transmit (output) to or receive (obtain) data from another interface that is configured to transmit or receive, respectively, the data.

FIGS. 4A, 4B, 4C, and 4D depict aspects of data structures for a wireless communications network, such as wireless communications network 100 of FIG. 1.

In particular, FIG. 4A is a diagram 400 illustrating an example of a first subframe within a 5G (e.g., 5G NR) frame structure, FIG. 4B is a diagram 430 illustrating an example of DL channels within a 5G subframe, FIG. 4C is a diagram 450 illustrating an example of a second subframe within a 5G frame structure, and FIG. 4D is a diagram 480 illustrating an example of UL channels within a 5G subframe.

Wireless communications systems may utilize orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on the uplink and downlink. Such systems may also support half-duplex operation using time division duplexing (TDD). OFDM and single-carrier frequency division multiplexing (SC-FDM) partition the system bandwidth (e.g., as depicted in FIGS. 4B and 4D) into multiple orthogonal subcarriers. Each subcarrier may be modulated with data. Modulation symbols may be sent in the frequency domain with OFDM and/or in the time domain with SC-FDM.

A wireless communications frame structure may be frequency division duplex (FDD), in which, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated for either DL or UL. Wireless communications frame structures may also be time division duplex (TDD), in which, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated for both DL and UL.

In FIGS. 4A and 4C, the wireless communications frame structure is TDD where Dis DL, U is UL, and X is flexible for use between DL/UL. UEs may be configured with a slot format through a received slot format indicator (SFI) (dynamically through DL control information (DCI), or semi-statically/statically through radio resource control (RRC) signaling). In the depicted examples, a 10 ms frame is divided into 10 equally sized 1 ms subframes. Each subframe may include one or more time slots. In some examples, each slot may include 7 or 14 symbols, depending on the slot format. Subframes may also include mini-slots, which generally have fewer symbols than an entire slot. Other wireless communications technologies may have a different frame structure and/or different channels.

In certain aspects, the number of slots within a subframe is based on a slot configuration and a numerology. For example, for slot configuration 0, different numerologies (μ) 0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology μ, there are 14 symbols/slot and 2μ slots/subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2^μ×15 kHz, where u is the numerology 0 to 5. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=5 has a subcarrier spacing of 480 kHz. The symbol length/duration is inversely related to the subcarrier spacing. FIGS. 4A, 4B, 4C, and 4D provide an example of slot configuration 0 with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs.

As depicted in FIGS. 4A, 4B, 4C, and 4D, a resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends, for example, 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 4A, some of the REs carry reference (pilot) signals (RS) for a UE (e.g., UE 104 of FIGS. 1 and 3). The RS may include demodulation RS (DMRS) and/or channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and/or phase tracking RS (PT-RS).

FIG. 4B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including, for example, nine RE groups (REGs), each REG including, for example, four consecutive REs in an OFDM symbol.

A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE (e.g., 104 of FIGS. 1 and 3) to determine subframe/symbol timing and a physical layer identity.

A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing.

Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DMRS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block. The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and/or paging messages.

As illustrated in FIG. 4C, some of the REs carry DMRS (indicated as R for one particular configuration, but other DMRS configurations are possible) for channel estimation at the base station. The UE may transmit DMRS for the PUCCH and DMRS for the PUSCH. The PUSCH DMRS may be transmitted, for example, in the first one or two symbols of the PUSCH. The PUCCH DMRS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. UE 104 may transmit sounding reference signals (SRS). The SRS may be transmitted, for example, in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

FIG. 4D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI.

FIG. 5 is a call-flow diagram 500 illustrating an example four-step RACH procedure, in accordance with certain aspects of the present disclosure. A first message (MSG1) may be sent from the UE 104 to BS 102 on the physical random access channel (PRACH). In this case, MSG1 may only include a RACH preamble 504. BS 102 may respond with a random access response (RAR) message 506 (MSG2) which may include the identifier (ID) of the RACH preamble, a timing advance (TA), an uplink grant, cell radio network temporary identifier (C-RNTI), and a back off indicator (BI). MSG2 may include a PDCCH communication including control information for (e.g., scheduling a reception of) a following communication on the PDSCH, as illustrated. In response to MSG2, MSG3 is transmitted from the UE 104 to BS 102 on the PUSCH 508. MSG3 may include one or more of an RRC connection request, a tracking area update request, a system information request, a positioning fix or positioning signal request, or a scheduling request. The BS 102 then responds with MSG4 which may include a contention resolution message 510. In some cases, the UE 104 may also receive system information 502 (e.g., also referred to herein as a system information message) indicating various communication parameters that may be used by the UE 104 for communicating with the BS 102.

FIG. 6 depicts an example association (mapping) of SSBs 602 to RACH occasions (ROs) 604. This SSB to RO association is used for the gNB to know what beam the UE has acquired/is using (generally referred to as beam establishment). One SSB may be associated with one or more ROs or more than one SSB may be associated with one RO. Association is typically performed in the frequency domain first, then in the time domain within a RACH slot, then in the time domain across RACH slots (e.g., beginning with lower SSB indexes). An association period is typically defined as a minimum number of RACH configuration periods, such that all (configured) SSB beams are mapped into ROs.

In some cases, SSBs/beams detected in one BWP may be mapped to ROs in another BWP. In such cases, aspects of the present disclosure may adjust PRACH related timing to account for BWP switching (e.g., extending a timeline in which the UE is expected to transmit a PRACH to account for additional BWP switching delay).

Aspects Related to Differentiating PRACH Repetition Numbers

As noted above, to increase the chance of successful decoding, a PRACH may be sent with repetition, allowing a base station (gNB) to perform combining of signals received over multiple ROs. A higher number of repetitions can increase the chance of successful communication, but it also increases the UE's power consumption and delay. The number of PRACH repetitions may determine a size of the RAR window.

As noted above, in some cases, a UE has the flexibility to select the number of PRACH repetitions. In such cases, the network entity may need to know how many PRACH repetitions will be sent, for example, so the UE and gNB can be in agreement regarding the RAR window. Further, the gNB not knowing the number of PRACH repetitions may impact gNB performance. For example, the gNB may not take advantage of potential decoding gain by combining PRACH transmissions and/or the gNB may waste resources attempting blind decoding.

Aspects of the present disclosure provide techniques for differentiating PRACH repetition numbers, which may help resolve the ambiguity at the UE and gNB. For example, a number of PRACH repetitions in a group may be determined based on at least one resource associated with at least one PRACH repetition of the group of PRACH repetitions.

The techniques proposed herein may be understood with reference to the call flow diagram 700 of FIG. 7. The UE and network entity depicted in FIG. 7 may be examples of UE 104 and BS 102 depicted and described with respect to FIG. 1 and FIG. 3. The network entity may also be an example of a node of a disaggregated base station depicted and described with respect to FIG. 2.

As shown at 702, the UE may select at least one resource for at least one physical random access channel (PRACH) repetition of a group of PRACH repetitions, based on a number of PRACH repetitions in the group.

The UE may then transmit the number of PRACH repetitions in accordance with the selection of the at least one resource. In other words, the resource may be selected to indicate the number of PRACH repetitions.

Therefore, as shown at 704, network entity may determine the number of PRACH repetitions, based on at least one resource associated with the at least one PRACH repetition, and process the group of PRACH repetitions in accordance with the determination.

Any suitable resource may be used to indicate the number of PRACH repetitions. For example, the resource may be a PRACH preamble or a PRACH preamble subset. In such cases, the network entity may determine the number of PRACH repetitions based on which subset a decoded PRACH belongs to.

In some cases, the resource may be a time domain location or a frequency domain location of a random access channel (RACH) occasion (RO) or a RO group in which the at least one PRACH repetition is transmitted (and received by the network entity). In some cases, the at least one resource may be a time domain location or a frequency domain location of a starting RO or an ending RO of the RO group.

According to certain aspects, the determination may be based on at least one of a time domain location or a frequency domain location of a starting RO or an ending RO of the RO group. In some cases, the number of PRACH repetitions may be determined based on a RACH RO group in which the at least one PRACH repetition was received, where different RO groups may be associated with different numbers of PRACH repetitions.

Additionally, as shown at 706, the network entity may determine a random access response (RAR) window based on the determination. According to certain aspects, the RAR window may be determined based on an RO group, of the different RO groups, associated with a largest number of PRACH repetitions. The UE may also determine the RAR window, and monitor for a RAR within the RAR window. According to certain aspects, the UE may determine the RAR window based on the number of PRACH repetitions in the group.

As illustrated, the network entity may transmit a RAR within the RAR window. In some cases, the RAR may convey a Random Access Response Radio Network Temporary Identifier (RA-RNTI), which may be determined based on the number of PRACH repetitions in the group. In some cases, the RA-RNTI may be dependent on the number of PRACH repetitions in the group, which may be based on a dependence on a frequency location (starting RB) of the PRACH repetitions.

As noted above, different PRACH repetition numbers may be differentiated based on their associated preamble subset and/or their associated RO group. In some cases, multiple PRACH repetition numbers (e.g., predefined and/or preconfigured values) may be configured by a network entity (e.g., a gNB) and/or specified in wireless communications standards, where one repetition number is selected by UE and PRACH repetitions are transmitted using associated preambles and/or associated RO groups. In some cases the selection of a repetition number (among the set of predefined and/or preconfigured values) may be done by UE based on criteria configured by gNB.

As noted above, differentiating between different PRACH repetition numbers may be based on different preamble subsets. According to certain aspects, different PRACH preamble subsets, associated with different numbers of PRACH repetitions, may be partitioned from a larger set of PRACH preambles associated with PRACH repetition.

In some cases, a number of PRACH repetitions associated with a given PRACH preamble subset may be based, at least in part, on the number of PRACH preambles in that PRACH preamble subset. In some cases, a predefined rule (e.g., in a wireless communications standard) may determine the preamble subset based on the number of preambles in each subset. For example, preamble subsets associated with different repetition numbers may be configured as partitions of a larger subset associated with PRACH repetition.

This approach may be understood by considering an example where a total number of k preambles are associated with PRACH repetition. In some cases, these k preambles may be shifted versions (e.g., with a preconfigured offset) of other preambles (e.g., used for PRACH without repetition).

The k preambles may be split between different numbers of PRACH repetitions. For example, k-k2 of the k preambles may be allocated for a first number n1 of PRACH repetitions, while the remaining k2 preambles may be allocated for a second number n2 of PRACH repetitions. Based on this allocation, a gNB may be able to determine the number of PRACH repetitions, based on the PRACH preamble detected. In other words, if the gNB detects one of the k-k2 preambles allocated to n1, it can expect n1 PRACH repetitions. On the other hand, if the gNB detects one of the k2 preambles allocated to n2, it can expect n2 PRACH repetitions.

As noted above, PRACH repetition numbers may be differentiated based on at least one of a time domain location or a frequency domain location of a random access channel (RACH) occasion (RO) or a RO group, in which the at least one PRACH repetition was received.

FIG. 8 depicts an example of differentiating PRACH repetition numbers based on the frequency domain location of ROs used to transmit PRACH repetitions, in accordance with certain aspects of the present disclosure. In the example shown in FIG. 8, different repetition numbers may be differentiated based on frequency location (e.g., a starting resource block (RB)).

As illustrated at 802, if a PRACH repetition (RO0-RO3) is received in a first frequency domain location (e.g., a first starting RB), then a network entity may determine that there will be 4 PRACH repetitions (an RO bundle of size 4). On the other hand, as illustrated at 804, if a PRACH repetition is received in a second frequency domain location (e.g., a second starting RB), then the network entity may determine that there will be 2 PRACH repetitions (e.g., an RO bundle of size 2). As illustrated, for an RO bundle size of 2, the two PRACH repetitions could be sent on RO0 and RO1 or RO2 and RO3.

FIG. 9 depicts an example of differentiating PRACH repetition numbers based on time domain locations of ROs, in accordance with certain aspects of the present disclosure.

In this example, differentiation between different PRACH repetition numbers may be done by nested RO groupings with a starting or ending RO dependent on repetition number. For example, different repetition numbers may be differentiated based on time domain location of ROs in which a PRACH repetition is received.

As illustrated, if a PRACH repetition is received in RO 0 in a first time domain location 902, then a network entity may determine that there will be 4 PRACH repetitions, received in an RO bundle (consisting of RO 0, RO 1, RO 2, and RO 3) of size 4. On the other hand, if a PRACH repetition is not received in RO 0 in the first time domain location 902, but a PRACH repetition is received in RO 2 in a second time domain location 904, then the network entity may determine that there will be 2 PRACH repetitions received in an RO bundle (consisting of RO 2 and RO 3) of size 2. This also limits the number of blind decodes, as the network entity may monitor RO 0 and RO 2 for PRACH repetitions and only monitor other ROs if a PRACH repetition is detected on RO 0 or RO 2.

According to certain aspects, association of different RO bundle locations in time may be done such that an RAR window starts independently/irrespective of repetition number. For example, a start of an RAR window may be based on a grouping of ROs in time with the largest PRACH repetition number (not the actual repetition number that is used for PRACH transmission). In other words, the RAR window may be determined based on an RO group, of the different RO groups, associated with a largest number of PRACH repetitions.

As noted above, the RAR may convey a Random Access Response Radio Network Temporary Identifier (RA-RNTI). In some cases, the RA-RNTI is determined based on the number of PRACH repetitions in the group. In some cases, RA-RNTI may be dependent on the number of PRACH repetitions, based on the location of a starting copy or a last copy of the PRACH repetitions in time.

Example Operations

FIG. 10 shows an example of a method 1000 of wireless communications by a network entity, such as a BS 102 of FIGS. 1 and 3, or a disaggregated base station as discussed with respect to FIG. 2.

Method 1000 begins at step 1005 with receiving at least one PRACH repetition, of a group of PRACH repetitions. In some cases, the operations of this step refer to, or may be performed by, circuitry for receiving and/or code for receiving as described with reference to FIG. 12.

Method 1000 then proceeds to step 1010 with determining a number of PRACH repetitions in the group, based on at least one resource associated with the at least one PRACH repetition. In some cases, the operations of this step refer to, or may be performed by, circuitry for determining and/or code for determining as described with reference to FIG. 12.

Method 1000 then proceeds to step 1015 with processing the group of PRACH repetitions, in accordance with the determination. In some cases, the operations of this step refer to, or may be performed by, circuitry for processing and/or code for processing as described with reference to FIG. 12.

In some aspects, the at least one resource comprises at least one of a PRACH preamble or a PRACH preamble subset.

In some aspects, different PRACH preamble subsets, associated with different numbers of PRACH repetitions, are partitioned from a larger set of PRACH preambles associated with PRACH repetition.

In some aspects, a number of PRACH repetitions associated with a given PRACH preamble subset is based, at least in part, on the number of PRACH preambles in that PRACH preamble subset.

In some aspects, the at least one resource comprises at least one of a time domain location or a frequency domain location of a RO or a RO group, in which the at least one PRACH repetition was received.

In some aspects, the determination is based on at least one of a time domain location or a frequency domain location of a starting RO or an ending RO of the RO group.

In some aspects, one or more RO groups are nested within a larger RO group; and the determination is based on whether the at least one PRACH repetition was received in a nested RO group or the larger RO group.

In some aspects, the method 1000 further includes determining a RAR window. In some cases, the operations of this step refer to, or may be performed by, circuitry for determining and/or code for determining as described with reference to FIG. 12.

In some aspects, the method 1000 further includes transmitting a RAR within the RAR window. In some cases, the operations of this step refer to, or may be performed by, circuitry for transmitting and/or code for transmitting as described with reference to FIG. 12.

In some aspects, the RAR window is determined based on the determined number of PRACH repetitions.

In some aspects, the number of PRACH repetitions is determined based on a RO group in which the at least one PRACH repetition was received, wherein different RO groups are associated with different numbers of PRACH repetitions; and the RAR window is determined based on an RO group, of the different RO groups, associated with a largest number of PRACH repetitions.

In some aspects, the RAR conveys a RA-RNTI; and the RA-RNTI is determined based on the number of PRACH repetitions in the group.

In one aspect, method 1000, or any aspect related to it, may be performed by an apparatus, such as communications device 1200 of FIG. 12, which includes various components operable, configured, or adapted to perform the method 1000. Communications device 1200 is described below in further detail.

Note that FIG. 10 is just one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

FIG. 11 shows an example of a method 1100 of wireless communications by a UE, such as a UE 104 of FIGS. 1 and 3.

Method 1100 begins at step 1105 with selecting at least one resource for at least one PRACH repetition of a group of PRACH repetitions, wherein the selection is based on a number of PRACH repetitions in the group. In some cases, the operations of this step refer to, or may be performed by, circuitry for selecting and/or code for selecting as described with reference to FIG. 12.

Method 1100 then proceeds to step 1110 with transmitting the PRACH repetitions, in accordance with the selection. In some cases, the operations of this step refer to, or may be performed by, circuitry for transmitting and/or code for transmitting as described with reference to FIG. 12.

In some aspects, the at least one resource comprises at least one of a PRACH preamble or a PRACH preamble subset.

In some aspects, different PRACH preamble subsets, associated with different numbers of PRACH repetitions, are partitioned from a larger set of PRACH preambles associated with PRACH repetition.

In some aspects, a number of PRACH repetitions associated with a given PRACH preamble subset is based, at least in part, on the number of PRACH preambles in that PRACH preamble subset.

In some aspects, the at least one resource comprises at least one of a time domain location or a frequency domain location of a RO or a RO group, in which the at least one PRACH repetition was transmitted.

In some aspects, the at least one resource comprises a time domain location or a frequency domain location of a starting RO or an ending RO of the RO group.

In some aspects, one or more RO groups are nested within a larger RO group; and the selection is based on whether the number of PRACH repetitions is associated with a nested RO group or the larger RO group.

In some aspects, the method 1100 further includes determining a RAR window. In some cases, the operations of this step refer to, or may be performed by, circuitry for determining and/or code for determining as described with reference to FIG. 12.

In some aspects, the method 1100 further includes monitoring for a RAR within the RAR window. In some cases, the operations of this step refer to, or may be performed by, circuitry for monitoring and/or code for monitoring as described with reference to FIG. 12.

In some aspects, the RAR window is determined based on the determined number of PRACH repetitions.

In some aspects, the selection is based on a RO group associated with the number of PRACH repetitions, wherein different RO groups are associated with different numbers of PRACH repetitions; and the RAR window is determined based on an RO group, of the different RO groups, associated with a largest number of PRACH repetitions.

In some aspects, the UE monitors for an RAR that conveys a RA-RNTI; and the RA-RNTI is determined based on the number of PRACH repetitions in the group.

In one aspect, method 1100, or any aspect related to it, may be performed by an apparatus, such as communications device 1200 of FIG. 12, which includes various components operable, configured, or adapted to perform the method 1100. Communications device 1200 is described below in further detail.

Note that FIG. 11 is just one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

Example Communications Device

FIG. 12 depicts aspects of an example communications device 1200. In some aspects, communications device 1200 is a user equipment, such as UE 104 described above with respect to FIGS. 1 and 3. In some aspects, communications device 1200 is a network entity, such as BS 102 of FIGS. 1 and 3, or a disaggregated base station as discussed with respect to FIG. 2.

The communications device 1200 includes a processing system 1202 coupled to the transceiver 1234 (e.g., a transmitter and/or a receiver). In some aspects (e.g., when communications device 1200 is a network entity), processing system 1202 may be coupled to a network interface 1238 that is configured to obtain and send signals for the communications device 1200 via communication link(s), such as a backhaul link, midhaul link, and/or fronthaul link as described herein, such as with respect to FIG. 2. The transceiver 1234 is configured to transmit and receive signals for the communications device 1200 via the antenna 1236, such as the various signals as described herein. The processing system 1202 may be configured to perform processing functions for the communications device 1200, including processing signals received and/or to be transmitted by the communications device 1200.

The processing system 1202 includes one or more processors 1204. In various aspects, the one or more processors 1204 may be representative of one or more of receive processor 358, transmit processor 364, TX MIMO processor 366, and/or controller/processor 380, as described with respect to FIG. 3. In various aspects, one or more processors 1204 may be representative of one or more of receive processor 338, transmit processor 320, TX MIMO processor 330, and/or controller/processor 340, as described with respect to FIG. 3. The one or more processors 1204 are coupled to a computer-readable medium/memory 1218 via a bus 1232. In certain aspects, the computer-readable medium/memory 1218 is configured to store instructions (e.g., computer-executable code) that when executed by the one or more processors 1204, cause the one or more processors 1204 to perform the method 1000 described with respect to FIG. 10, or any aspect related to it; and the method 1100 described with respect to FIG. 11, or any aspect related to it. Note that reference to a processor performing a function of communications device 1200 may include one or more processors 1204 performing that function of communications device 1200.

In the depicted example, computer-readable medium/memory 1218 stores code (e.g., executable instructions), such as code for receiving 1220, code for determining 1222, code for processing 1224, code for transmitting 1226, code for selecting 1228, and code for monitoring 1230. Processing of the code for receiving 1220, code for determining 1222, code for processing 1224, code for transmitting 1226, code for selecting 1228, and code for monitoring 1230 may cause the communications device 1200 to perform the method 1000 described with respect to FIG. 10, or any aspect related to it; and the method 1100 described with respect to FIG. 11, or any aspect related to it.

The one or more processors 1204 include circuitry configured to implement (e.g., execute) the code stored in the computer-readable medium/memory 1218, including circuitry for receiving 1206, circuitry for determining 1208, circuitry for processing 1210, circuitry for transmitting 1212, circuitry for selecting 1214, and circuitry for monitoring 1216. Processing with circuitry for receiving 1206, circuitry for determining 1208, circuitry for processing 1210, circuitry for transmitting 1212, circuitry for selecting 1214, and circuitry for monitoring 1216 may cause the communications device 1200 to perform the method 1000 described with respect to FIG. 10, or any aspect related to it; and the method 1100 described with respect to FIG. 11, or any aspect related to it.

Various components of the communications device 1200 may provide means for performing the method 1000 described with respect to FIG. 10, or any aspect related to it; and the method 1100 described with respect to FIG. 11, or any aspect related to it. For example, means for transmitting, sending or outputting for transmission may include transceivers 354 and/or antenna(s) 352 of the UE 104 illustrated in FIG. 3, transceivers 332 and/or antenna(s) 334 of the BS 102 illustrated in FIG. 3, and/or the transceiver 1234 and the antenna 1236 of the communications device 1200 in FIG. 12. Means for receiving or obtaining may include transceivers 354 and/or antenna(s) 352 of the UE 104 illustrated in FIG. 3, transceivers 332 and/or antenna(s) 334 of the BS 102 illustrated in FIG. 3, and/or the transceiver 1234 and the antenna 1236 of the communications device 1200 in FIG. 12.

EXAMPLE CLAUSES

Implementation examples are described in the following numbered clauses:

• • Clause 1: A method for wireless communications by a network entity, comprising: receiving at least one PRACH repetition, of a group of PRACH repetitions; determining a number of PRACH repetitions in the group, based on at least one resource associated with the at least one PRACH repetition; and processing the group of PRACH repetitions, in accordance with the determination.
  • Clause 2: The method of Clause 1, wherein the at least one resource comprises at least one of a PRACH preamble or a PRACH preamble subset.
  • Clause 3: The method of Clause 2, wherein different PRACH preamble subsets, associated with different numbers of PRACH repetitions, are partitioned from a larger set of PRACH preambles associated with PRACH repetition.
  • Clause 4: The method of Clause 2, wherein a number of PRACH repetitions associated with a given PRACH preamble subset is based, at least in part, on the number of PRACH preambles in that PRACH preamble subset.
  • Clause 5: The method of any one of Clauses 1-4, wherein the at least one resource comprises at least one of a time domain location or a frequency domain location of a RO or a RO group, in which the at least one PRACH repetition was received.
  • Clause 6: The method of Clause 5, wherein the determination is based on at least one of a time domain location or a frequency domain location of a starting RO or an ending RO of the RO group.
  • Clause 7: The method of Clause 5, wherein: one or more RO groups are nested within a larger RO group; and the determination is based on whether the at least one PRACH repetition was received in a nested RO group or the larger RO group.
  • Clause 8: The method of any one of Clauses 1-7, further comprising: determining a RAR window; and transmitting a RAR within the RAR window.
  • Clause 9: The method of Clause 8, wherein the RAR window is determined based on the determined number of PRACH repetitions.
  • Clause 10: The method of Clause 8, wherein: the number of PRACH repetitions is determined based on a RO group in which the at least one PRACH repetition was received, wherein different RO groups are associated with different numbers of PRACH repetitions; and the RAR window is determined based on an RO group, of the different RO groups, associated with a largest number of PRACH repetitions.
  • Clause 11: The method of Clause 8, wherein: the RAR conveys a RA-RNTI; and the RA-RNTI is determined based on the number of PRACH repetitions in the group.
  • Clause 12: A method for wireless communications by a UE, comprising: selecting at least one resource for at least one PRACH repetition of a group of PRACH repetitions, wherein the selection is based on a number of PRACH repetitions in the group; and transmitting the PRACH repetitions, in accordance with the selection.
  • Clause 13: The method of Clause 12, wherein the at least one resource comprises at least one of a PRACH preamble or a PRACH preamble subset.
  • Clause 14: The method of Clause 13, wherein different PRACH preamble subsets, associated with different numbers of PRACH repetitions, are partitioned from a larger set of PRACH preambles associated with PRACH repetition.
  • Clause 15: The method of Clause 13, wherein a number of PRACH repetitions associated with a given PRACH preamble subset is based, at least in part, on the number of PRACH preambles in that PRACH preamble subset.
  • Clause 16: The method of any one of Clauses 12-15, wherein the at least one resource comprises at least one of a time domain location or a frequency domain location of a RO or a RO group, in which the at least one PRACH repetition was transmitted.
  • Clause 17: The method of Clause 16, wherein the at least one resource comprises a time domain location or a frequency domain location of a starting RO or an ending RO of the RO group.
  • Clause 18: The method of Clause 16, wherein: one or more RO groups are nested within a larger RO group; and the selection is based on whether the number of PRACH repetitions is associated with a nested RO group or the larger RO group.
  • Clause 19: The method of any one of Clauses 12-18, further comprising: determining a RAR window; and monitoring for a RAR within the RAR window.
  • Clause 20: The method of Clause 19, wherein the RAR window is determined based on the determined number of PRACH repetitions.
  • Clause 21: The method of Clause 19, wherein: the selection is based on a RO group associated with the number of PRACH repetitions, wherein different RO groups are associated with different numbers of PRACH repetitions; and the RAR window is determined based on an RO group, of the different RO groups, associated with a largest number of PRACH repetitions.
  • Clause 22: The method of Clause 19, wherein: the UE monitors for an RAR that conveys a RA-RNTI; and the RA-RNTI is determined based on the number of PRACH repetitions in the group.
  • Clause 23: An apparatus, comprising: a memory comprising executable instructions; and a processor configured to execute the executable instructions and cause the apparatus to perform a method in accordance with any one of Clauses 1-22.
  • Clause 24: An apparatus, comprising means for performing a method in accordance with any one of Clauses 1-22.
  • Clause 25: A non-transitory computer-readable medium comprising executable instructions that, when executed by a processor of an apparatus, cause the apparatus to perform a method in accordance with any one of Clauses 1-22.
  • Clause 26: A computer program product embodied on a computer-readable storage medium comprising code for performing a method in accordance with any one of Clauses 1-22.

ADDITIONAL CONSIDERATIONS

The preceding description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples discussed herein are not limiting of the scope, applicability, or aspects set forth in the claims. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. For example, changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various actions may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method that is practiced using other structure, functionality, or structure and functionality in addition to, or other than, the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

The various illustrative logical blocks, modules and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, a system on a chip (SoC), or any other such configuration.

As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “determining” encompasses a wide variety of actions. For example, “determining” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “determining” may include resolving, selecting, choosing, establishing and the like.

The methods disclosed herein comprise one or more actions for achieving the methods. The method actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of actions is specified, the order and/or use of specific actions may be modified without departing from the scope of the claims. Further, the various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software component(s) and/or module(s), including, but not limited to a circuit, an application specific integrated circuit (ASIC), or processor.

The following claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims. Within a claim, reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f) unless the element is expressly recited using the phrase “means for”. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.